CN110699722A - Preparation of Ti5Si3Method for producing high temperature alloy film - Google Patents

Abstract

The invention discloses a method for preparing a Ti ₅ Si ₃ superalloy film, which belongs to the technical field of metallurgy. Calcium is used as a co-solvent to form an electrodeposition system; (2) the graphite sheet is used as the cathode and the graphite rod is used as the anode, and the Ti ₅ Si ₃ superalloy film is prepared by electrodeposition under the condition of constant current/constant voltage at 850°C; (3) the present invention The Ti ₅ Si ₃ superalloy film with adjustable thickness can be continuously prepared by periodically adding silicon dioxide and titanium dioxide raw materials. The invention can directly prepare the ultra-high melting point superalloy dense film/coating at a lower temperature (850°C), and at the same time, the film thickness and microscopic morphology can be controlled by changing parameters such as current density and electrodeposition time. . The method of the invention has the characteristics of short process flow, low energy consumption and the like.

Description

A kind of method for preparing Ti5Si3 superalloy film

technical field

The invention relates to the technical field of metallurgy, in particular to a method for preparing a Ti ₅ Si ₃ superalloy film.

Background technique

As a typical intermetallic compound of titanium and silicon, Ti ₅ Si ₃ has the characteristics of high melting point (2123 ° C), high strength, high hardness, good high temperature oxidation resistance, creep resistance, etc., and is widely used in aerospace, electronics, etc. Device materials, coating materials and other fields.

At present, there are many methods for preparing Ti ₅ Si ₃ powder, such as self-propagating high temperature synthesis (SHS), mechanical alloying (MA), spark plasma sintering (SPS) and so on. However, the preparation of Ti ₅ Si ₃ superalloy films has always been a difficult problem, mainly because the ultra-high melting point makes it difficult to prepare Ti ₅ Si ₃ superalloy films under melting conditions. At present, the methods for preparing Ti ₅ Si ₃ films mainly include thermal evaporation and atmospheric pressure chemical vapor deposition (APCVD). Among them, the thermal evaporation method is to heat the raw material to vaporize, and then deposit it on the surface of the substrate; this process can prepare a high-purity Ti ₅ Si ₃ film, but the required equipment is expensive and the degree of control is low. The APCVD method has the advantages of low production cost, simple device and wide coating area; however, this technology has strict requirements on the reaction system, complicated collection process of the deposited products, and poor controllability of the film quality.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to invent a method with simple requirements for the reaction system, simple collection of deposition products, and high quality reliability of the Ti ₅ Si ₃ film.

In order to achieve the above purpose, the present invention provides a method for preparing a Ti ₅ Si ₃ superalloy film, which is characterized in that it is carried out according to the following process steps:

a. Pretreatment of molten salt electrolyte: with anhydrous CaCl ₂ as molten salt medium, SiO ₂ and TiO ₂ as raw materials, CaO as auxiliary solvent, CaCl ₂ -(2-5%)SiO ₂ -(1-5% )TiO ₂ -(2-5%) CaO (mass percentage) is added to alumina crucible or quartz crucible, then heated under vacuum or inert atmosphere protection, and kept warm to remove crystal water in molten salt; then under inert atmosphere protection Heating to 850°C, keeping the temperature for 24-48h, so that the SiO ₂ and TiO ₂ raw materials are fully dissolved in the molten salt medium to form an electrodeposition system;

b. Pre-electrolysis to remove impurities: put graphite rods as anode and cathode, adjust the voltage to 2.5V for pre-electrolysis, and the pre-electrolysis time is 1-4h;

c. Electrodeposition of Ti ₅ Si ₃ superalloy film: A graphite rod is used as the anode, and the cathode matrix is electrodeposited with molten salt under the protective atmosphere of an inert atmosphere and a current density of 5–30 mA/cm ² .

Further, in the step b, the pre-electrolysis can be repeated as many times as needed.

Further, in the step c, the electrodeposition time can be adjusted from 1 to 24 h so as to directly obtain Ti ₅ Si ₃ superalloy films with different thicknesses.

Further, in the electrodeposition process in the step c, the thickness and microscopic morphology of the product can be controlled by changing the current density and the electrodeposition time, so as to obtain a dense Ti ₅ Si ₃ superalloy film.

Further, by periodically adding silicon dioxide and titanium dioxide raw materials, it is possible to continuously prepare a Ti ₅ Si ₃ superalloy film with adjustable thickness.

Further, the added silica and titania raw materials are micro/nano powders.

Further, Ti ₅ Si ₃ superalloy powder can also be prepared.

Further, the cathode substrate can be a substrate such as graphite and metal/alloy.

Further, heating to 400-600°C under the protection of vacuum or inert atmosphere.

Further, the time for the heat preservation to remove crystal water in the molten salt is 12-24h.

Compared with the prior art, the present invention has the following advantages: short process flow, low energy consumption, no pollution, low preparation cost, and good product controllability _; and TiO ₂ ) electrodeposition to prepare Ti ₅ Si ₃ superalloy film and Ti ₅ Si ₃ powder, whose thickness and microstructure can be controlled.

The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, characteristics and effects of the present invention.

Description of drawings

1 is a SEM image of a Ti ₅ Si ₃ superalloy film prepared in a preferred embodiment of the present invention;

2 is an EDS surface scan of the cross section of the Ti ₅ Si ₃ superalloy film prepared in a preferred embodiment of the present invention;

3 is an XRD pattern of a Ti ₅ Si ₃ superalloy film prepared in a preferred embodiment of the present invention;

Fig. 4 is the SEM image of the cross section of the Ti ₅ Si ₃ superalloy film prepared in a preferred embodiment 2 of the present invention;

Fig. 5 is the SEM image of the cross section of the Ti ₅ Si ₃ superalloy film prepared in a preferred embodiment 3 of the present invention;

6 is a SEM image of the cross section of the Ti ₅ Si ₃ superalloy film prepared in a preferred embodiment 4 of the present invention;

Fig. 7 is the SEM image of dendritic Ti ₅ Si ₃ prepared in a preferred embodiment 5 of the present invention;

Fig. 8 is the EDS figure of the dendritic Ti ₅ Si ₃ prepared by a preferred embodiment 5 of the present invention;

9 is a SEM image and an EDS image of granular Ti ₅ Si ₃ prepared in a preferred embodiment 6 of the present invention.

Detailed ways

The following describes several preferred embodiments of the present invention with reference to the accompanying drawings, so as to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned herein.

In the drawings, structurally identical components are denoted by the same numerals, and structurally or functionally similar components are denoted by like numerals throughout. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component.

A preferred embodiment one of the present invention:

In this embodiment, a method for directly preparing Ti ₅ Si ₃ superalloy film by low-temperature molten salt electrodeposition is mainly introduced. The specific operation steps are as follows:

a. Pretreatment of molten salt electrolyte: take 100g anhydrous CaCl ₂ as molten salt medium, 2.0g SiO ₂ and 2.0g TiO ₂ as raw materials, 2.0g CaO as auxiliary solvent, add the above substances into a quartz crucible, and then place it in a Vertical resistance furnace. Heating to 400–500 °C in vacuum, holding for 12–24 h to remove crystal water in the molten salt; then heating to 850 °C under the protection of high-purity argon, holding for 24–48 h, so that the SiO ₂ and TiO ₂ raw materials are melted in the molten salt. Fully dissolved in salt medium;

b. Pre-electrolysis to remove impurities: two graphite rods are used as cathode and anode, and pre-electrolysis is carried out under the condition of 2.5V, and the pre-electrolysis time is 4h;

c. Electrodeposition of Ti ₅ Si ₃ superalloy film: with high-purity graphite sheet as cathode matrix and graphite rod as anode, under the protective atmosphere of high-purity argon, the current density is adjusted to 15mA/cm ² , and molten salt electrodeposition is carried out , the product was obtained after electrodeposition for 4 h. The SEM image is shown in Figure 1, the EDS surface scan energy spectrum is shown in Figure 2, and the XRD pattern is shown in Figure 3, which proves that the Ti ₅ Si ₃ film is obtained by deposition.

A preferred embodiment two of the present invention:

In this embodiment, a method for directly preparing Ti ₅ Si ₃ superalloy film by low-temperature molten salt electrodeposition is mainly introduced. The specific operation steps are as follows:

a. Pretreatment of molten salt electrolyte: this step is the same as in Example 1;

b. Pre-electrolysis to remove impurities: this step is the same as the first embodiment;

c. Electrodeposition of Ti ₅ Si ₃ superalloy film: take high-purity graphite sheet as cathode matrix and graphite rod as anode, under argon protective atmosphere, adjust the current density to ~15mA/cm ² to conduct molten salt electrodeposition, The product was obtained after electrodeposition for 1 h, and its SEM image is shown in FIG. 4 .

A preferred embodiment three of the present invention:

In this embodiment, a method for directly preparing Ti ₅ Si ₃ superalloy film by low-temperature molten salt electrodeposition is mainly introduced. The specific operation steps are as follows:

a. Pretreatment of molten salt electrolyte: this step is the same as in Example 1;

b. Pre-electrolysis to remove impurities: this step is the same as the first embodiment;

c. Electrodeposition of Ti ₅ Si ₃ superalloy film: with high-purity graphite sheet as cathode matrix, graphite rod as anode, under argon protective atmosphere, the current density is adjusted to 15mA/cm ² , and molten salt electrodeposition is carried out. The product was obtained after 3 h of deposition, and its SEM image is shown in FIG. 5 .

A preferred embodiment four of the present invention:

In this embodiment, a method for directly preparing Ti ₅ Si ₃ superalloy film by low-temperature molten salt electrodeposition is mainly introduced. The specific operation steps are as follows:

a. Pretreatment of molten salt electrolyte: this step is the same as in Example 1;

b. Pre-electrolysis to remove impurities: this step is the same as the first embodiment;

c. Electrodeposition of Ti ₅ Si ₃ superalloy film: with high-purity graphite sheet as cathode matrix, graphite rod as anode, under argon protective atmosphere, the current density is adjusted to 15mA/cm ² , and molten salt electrodeposition is carried out. The product was obtained after 5 h of deposition, and its SEM image is shown in Figure 6.

A preferred embodiment five of the present invention:

In this embodiment, a method for directly preparing Ti ₅ Si ₃ superalloy film by low-temperature molten salt electrodeposition is mainly introduced. The specific operation steps are as follows:

a. Pretreatment of molten salt electrolyte: this step is the same as in Example 1;

b. Pre-electrolysis to remove impurities: this step is the same as the first embodiment;

c. Electrodeposition of Ti ₅ Si ₃ superalloy film: with high-purity graphite sheet as cathode matrix, graphite rod as anode, under argon protective atmosphere, the current density is adjusted to 10mA/cm ² , and molten salt electrodeposition is carried out. The dendritic product was obtained after 3 h of deposition, the SEM image of which is shown in Fig. 7 and the EDS image as shown in Fig. 8 .

A preferred embodiment six of the present invention:

In this embodiment, a method for directly preparing Ti ₅ Si ₃ superalloy film by low-temperature molten salt electrodeposition is mainly introduced. The specific operation steps are as follows:

a. Pretreatment of molten salt electrolyte: this step is the same as in Example 1;

b. Pre-electrolysis to remove impurities: this step is the same as the first embodiment;

c. Electrodeposition of Ti ₅ Si ₃ superalloy powder: with high-purity graphite sheet as cathode matrix, graphite rod as anode, under argon protective atmosphere, the current density is adjusted to 25mA/cm ² , and molten salt electrodeposition is carried out. A granular product was obtained after deposition for 3 hours, and its SEM image and EDS surface scan energy spectrum are shown in FIG. 9 .

Compared with the prior art, the present invention has the following advantages: short process flow, low energy consumption, no pollution, low preparation cost, and good product _{controllability ;} ) Electrodeposition prepares two products, Ti ₅ Si ₃ superalloy film and Ti ₅ Si ₃ powder, whose thickness and microstructure can be controlled.

The preferred embodiments of the present invention have been described in detail above. It should be understood that many modifications and changes can be made according to the concept of the present invention by those skilled in the art without creative efforts. Therefore, any technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the prior art according to the concept of the present invention shall fall within the protection scope determined by the claims.

Claims (10)

1. Preparation of Ti₅Si₃The method for preparing the high-temperature alloy film is characterized by comprising the following steps of:

a. pretreatment of molten salt electrolyte: with anhydrous CaCl₂As a molten salt medium, SiO₂、TiO₂Taking CaO as an auxiliary solvent as a raw material, and adding CaCl₂-(2-5％)SiO₂-(1-5％)TiO₂Adding (2-5%) CaO (mass percent) into an alumina crucible or a quartz crucible, then heating under the protection of vacuum or inert atmosphere, and keeping the temperature to remove crystal water in molten salt; heating to 850 deg.C under the protection of inert atmosphere, and maintaining the temperature for 24-48 h to make SiO₂、TiO₂The raw materials are fully dissolved in a molten salt medium to form an electrodeposition system;

b. pre-electrolysis impurity removal: putting a graphite rod as an anode and a cathode, adjusting the voltage to 2.5V, and pre-electrolyzing for 1-4 h;

c. electrodeposition of Ti₅Si₃High-temperature alloy film: adopting graphite rod as anode, cathode matrix in inert atmosphere and current density of 5-30 mA/cm²And carrying out fused salt electrodeposition under the condition.

2. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that the step b, pre-electrolysis can be repeated for a plurality of times according to the requirement.

3. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that in the step c, the electrodeposition time is 1-24h is adjustable to directly obtain Ti with different thicknesses₅Si₃A high temperature alloy film.

4. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that the thickness and the micro appearance of a product can be controlled by changing the current density and the electrodeposition time in the electrodeposition process in the step c to obtain compact Ti₅Si₃A high temperature alloy film.

5. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that the Ti with adjustable thickness can be continuously prepared by periodically adding silicon dioxide and titanium dioxide raw materials₅Si₃A high temperature alloy film.

6. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that the added silicon dioxide and titanium dioxide raw materials are micron/nanometer powder.

7. Preparation of Ti according to claim 4₅Si₃A method for producing a high-temperature alloy film, characterized in that Ti is also produced₅Si₃High temperature alloy powder.

8. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that the cathode substrate can be graphite, metal/alloy and the like.

9. The method of claim 1, producing Ti₅Si₃The method for preparing the high-temperature alloy film is characterized in that the high-temperature alloy film is heated to 400-600 ℃ under the protection of vacuum or inert atmosphere.

10. The method of claim 1, producing Ti₅Si₃Method for the production of a superalloy film, characterised in that the heat is preserved to remove the molten saltThe time of the crystal water in the process is 12-24 h.

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